yes it is an emissions era carb & is lean & tweaking the innards does work excellent to fine tune em spot on but it can & will run at least on the idling circuit fine for the most part without em (& OP has a mild cam). there is another problem going on that needs to be fixed (something is severley damaged/leaking etc). I cant see fine tuning the innards with drilling fixing what is damaged. Like the one guy posted & my exp with em, they are fine but can be made better. if drilling mods fix this carb I'll be the first to admit I was wrong!